The present invention relates to resonant cavities and, more particularly, to a reconfigurable resonant cavity for use in conjunction with a slot antenna element to provide broadband operation of the antenna at more than one selected frequency band.
Slot radiators exhibit increased gain, typically 3 dB, when placed over a resonant cavity. Because the resonant cavity provides a high Q, the operational bandwidth of the system is limited.
Using a resonant cavity behind a slot is the primary solution for maximizing gain from a slot element.
It is, therefore, an object of the invention to provide a reconfigurable resonant cavity which results in high gain, broadband performance from an integrated slot radiator.
It is another object of the invention to provide a reconfigurable resonant cavity which includes movable xe2x80x9cfencesxe2x80x9d which define the effective size of the cavity.
It is a further object of the invention to provide a reconfigurable resonant cavity which implements xe2x80x9cfencesxe2x80x9d by using selectable shorting pins.
It is still another object of the invention to provide a reconfigurable resonant cavity which uses frequency- selective surface materials (FSS) to control the resonant frequency of the cavity.
In accordance with the present invention there is provided a reconfigurable resonant cavity for use with a slot radiator. Selectable, electrically conductive posts, operating in cooperation with FSS material, are used to define movable cavity walls, resulting in multiple, selectable, predetermined resonant frequencies of operation for the cavity. Microelectromechanical switches (MEMS) or other photonically or electrically operated switching devices are used to activate and deactivate the electrically conductive posts so as to effectively move the cavity walls.